Xie Longxiang, Wang Xiaobo, Zeng Jie, Zhou Mingliang, Duan Xiangke, Li Qiming, Zhang Zhen, Luo Hongping, Pang Lei, Li Wu, Liao Guojian, Yu Xia, Li Yunxu, Huang Hairong, Xie Jianping
Institute of Modern Biopharmaceuticals, State Key Laboratory Breeding Base of Eco-Environment and Bio-Resource of the Three Gorges Area, Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Ministry of Education, School of Life Sciences, Southwest University, Beibei, Chongqing 400715, China.
National Clinical Laboratory on Tuberculosis, Beijing Tuberculosis and Thoracic Tumor Research Institute, Beijing 101149, China.
Int J Biochem Cell Biol. 2015 Feb;59:193-202. doi: 10.1016/j.biocel.2014.11.010. Epub 2014 Nov 29.
N(ɛ)-Acetylation of lysine residues represents a pivotal post-translational modification used by both eukaryotes and prokaryotes to modulate diverse biological processes. Mycobacterium tuberculosis is the causative agent of tuberculosis, one of the most formidable public health threats. Many aspects of the biology of M. tuberculosis remain elusive, in particular the extent and function of N(ɛ)-lysine acetylation. With a combination of anti-acetyllysine antibody-based immunoaffinity enrichment with high-resolution mass spectrometry, we identified 1128 acetylation sites on 658 acetylated M. tuberculosis proteins. GO analysis of the acetylome showed that acetylated proteins are involved in the regulation of diverse cellular processes including metabolism and protein synthesis. Six types of acetylated peptide sequence motif were revealed from the acetylome. Twenty lysine-acetylated proteins showed homology with acetylated proteins previously identified from Escherichia coli, Salmonella enterica, Bacillus subtilis and Streptomyces roseosporus, with several acetylation sites highly conserved among four or five bacteria, suggesting that acetylated proteins are more conserved. Notably, several proteins including isocitrate lyase involved in the persistence, virulence and antibiotic resistance are acetylated, and site-directed mutagenesis of isocitrate lyase acetylation site to glutamine led to a decrease of the enzyme activity, indicating major roles of KAc in these proteins engaged cellular processes. Our data firstly provides a global survey of M. tuberculosis acetylation, and implicates extensive regulatory role of acetylation in this pathogen. This may serve as an important basis to address the roles of lysine acetylation in M. tuberculosis metabolism, persistence and virulence.
赖氨酸残基的N（ɛ）-乙酰化是真核生物和原核生物用于调节多种生物过程的关键翻译后修饰。结核分枝杆菌是结核病的病原体，结核病是最严重的公共卫生威胁之一。结核分枝杆菌生物学的许多方面仍然难以捉摸，尤其是N（ɛ）-赖氨酸乙酰化的程度和功能。通过基于抗乙酰赖氨酸抗体的免疫亲和富集与高分辨率质谱相结合的方法，我们在658个乙酰化的结核分枝杆菌蛋白上鉴定出1128个乙酰化位点。对乙酰化蛋白质组的基因本体（GO）分析表明，乙酰化蛋白参与包括代谢和蛋白质合成在内的多种细胞过程的调节。从乙酰化蛋白质组中揭示了六种类型的乙酰化肽序列基序。20种赖氨酸乙酰化蛋白与先前从大肠杆菌、肠炎沙门氏菌、枯草芽孢杆菌和玫瑰孢链霉菌中鉴定出的乙酰化蛋白具有同源性，其中几个乙酰化位点在四种或五种细菌中高度保守，这表明乙酰化蛋白更具保守性。值得注意的是，包括参与持续性、毒力和抗生素抗性的异柠檬酸裂解酶在内的几种蛋白质被乙酰化，将异柠檬酸裂解酶乙酰化位点定点突变为谷氨酰胺会导致酶活性降低，这表明赖氨酸乙酰化在这些参与细胞过程的蛋白质中起主要作用。我们的数据首次提供了结核分枝杆菌乙酰化的全面概况，并暗示了乙酰化在这种病原体中的广泛调节作用。这可能为阐明赖氨酸乙酰化在结核分枝杆菌代谢、持续性和毒力中的作用提供重要依据。
